1) Field of the Invention
The present invention provides a key structure, more especially, a key applied on a computer keyboard or a remote control.
2) Description of the Prior Art
Accordingly, the structure of a computer keyboard, as shown in FIG. 6 mainly includes a set of keys (A) moveably inserted into a connecting hole (B1) of an upper case (B); an elastic layer of silicone rubber (C) has a plurality of elastic convex bodies (C1) corresponding to the bottom portions of keys (A); an upper electric conducting membrane sheet (D) with an upper electrode connecting point (D1) printed and a circuit (D2) distributed on the surface thereof; a lower electric conducting membrane sheet (E) with a lower electrode connecting point (E1) printed and a circuit (E2) distributed on the surface thereof, an intermediate interfacing and isolating membrane sheet (F, an isolating piece) with a plurality of through holes (F1) disposed on the lower surface thereof; a bottom case (G) to be assembled with the upper case (B); wherein, when the key (A) is depressed, the elastic convex body (C1) contracts and deforms to further press the upper membrane sheet (D) to deform thereby to make the upper and the lower electrode connect points (D1, E1) contact each other via the through hole (F1) for electric conduction and signal transmission; when the force exerted on the key (A) is released, the elastic convex body (C1) and the upper membrane sheet (D) resume to the original position and the upper and the lower electrode connect points (D, E) resume and do not contact each other
The said keyboard has the following shortcomings after a long-term usage:
(1) Environmentally unfriendlyxe2x80x94The surfaces of the upper and the lower electric conducting membrane sheets (D, E) are printed with electric conducting electrode connecting points (D1, E1) made of rubber sheet in silver material and circuits (D2, E2); when the keyboard is discarded, the silver rubber material of the electric conducting membrane sheets (D, E) causes pollution which is hard to be handled; furthermore, the upper and the lower electric conducting membrane sheets (D, E) and the elastic rubber sheet (C) are hard to be decomposed after the keyboard is discarded for recycling.
(2) Increased costxe2x80x94In order to enable the key (A) to elastically displace up and down, four members (the elastic rubber sheet, the upper electric conducting membrane sheet, the lower electric conducting membrane sheet as well as the intermediate interfacing and isolating membrane sheet) are required and that tremendously increases the manufacturing
In view of the abovementioned shortcomings, the inventor of the present invention searched to not only maintain the key""s specialty of making elastic displacement up and down when it is depressed, but also eliminate the said four members.
Therefore, the primary objective of the present invention is to provide an improved key structure, simplify the parts and eliminate the upper and the lower electric conducting membrane sheets so as to efficiently reduce the pollution when the keyboard is discarded for recycling.
Another objective of the present invention is to provide an improved key structure for making precise descending and resuming movements of the key even after a long-term usage.
Yet another objective of the present invention is to provide an improved key structure for simplifying the components of the key structure thereby to reduce the manufacturing cost.
To enable a further understanding of the structural features, the objectives and the effects of the present invention, the brief description of the drawings below is followed by the detailed description of the preferred embodiment.